python pyparsing string：A，b，b，b，A，b，b，b * [关闭](python pyparsing string: A,b,b,b,A,b,b,b* [closed])

 我想回答我自己的问题：我认为我找到了一个合理的解决方案。 
 
 我不会在函数内部处理任何异常，我是从外部做的。 
 
private string GetSMTPAddressByFolderItem(Outlook.MAPIFolder mapiFolder)
    {

        string PR_MAILBOX_OWNER_ENTRYID = @"http://schemas.microsoft.com/mapi/proptag/0x661B0102";
        string PR_SMTP_ADDRESS = @"http://schemas.microsoft.com/mapi/proptag/0x39FE001E";

        Outlook.Store store = null;
        Outlook.NameSpace ns = null;
        Outlook.AddressEntry sender = null;
        Outlook._ExchangeUser exchUser = null;

        try
        {
            if (mapiFolder == null)
            {
                return null;
            }

            // Get the parent store.
            store = mapiFolder.Store;

            string storeOwnerEntryId = store.PropertyAccessor.BinaryToString(store.PropertyAccessor.GetProperty(PR_MAILBOX_OWNER_ENTRYID)) as string;
            ns = Application.GetNamespace(Constants.OL_NAMESPACE); // i.e. "MAPI"

            sender = ns.GetAddressEntryFromID(storeOwnerEntryId);

            if (sender != null)
            {
                if (sender.AddressEntryUserType == Outlook.OlAddressEntryUserType.olExchangeUserAddressEntry ||
                    sender.AddressEntryUserType == Outlook.OlAddressEntryUserType.olExchangeRemoteUserAddressEntry)
                {
                    exchUser = sender.GetExchangeUser();

                    if (exchUser != null)
                    {
                        return exchUser.PrimarySmtpAddress;
                    }
                    else
                    {
                        return null;
                    }
                }
                else
                {
                    return sender.PropertyAccessor.GetProperty(PR_SMTP_ADDRESS) as string;
                }
            }

            return null;
        }
        finally
        {
            if (ns != null)
            {
                Marshal.ReleaseComObject(ns);
                ns = null;
            }
            if (store != null)
            {
                Marshal.ReleaseComObject(store);
                store = null;
            }
            if (sender != null)
            {
                Marshal.ReleaseComObject(sender);
                sender = null;
            }
            if (exchUser != null)
            {
                Marshal.ReleaseComObject(exchUser);
                exchUser = null;
            }
        }
    }

I like to answer my own questions: I think that I've found a plausible solution.
 
I do not treat any exceptions inside the function, I do that from outside.
 
private string GetSMTPAddressByFolderItem(Outlook.MAPIFolder mapiFolder)
    {

        string PR_MAILBOX_OWNER_ENTRYID = @"http://schemas.microsoft.com/mapi/proptag/0x661B0102";
        string PR_SMTP_ADDRESS = @"http://schemas.microsoft.com/mapi/proptag/0x39FE001E";

        Outlook.Store store = null;
        Outlook.NameSpace ns = null;
        Outlook.AddressEntry sender = null;
        Outlook._ExchangeUser exchUser = null;

        try
        {
            if (mapiFolder == null)
            {
                return null;
            }

            // Get the parent store.
            store = mapiFolder.Store;

            string storeOwnerEntryId = store.PropertyAccessor.BinaryToString(store.PropertyAccessor.GetProperty(PR_MAILBOX_OWNER_ENTRYID)) as string;
            ns = Application.GetNamespace(Constants.OL_NAMESPACE); // i.e. "MAPI"

            sender = ns.GetAddressEntryFromID(storeOwnerEntryId);

            if (sender != null)
            {
                if (sender.AddressEntryUserType == Outlook.OlAddressEntryUserType.olExchangeUserAddressEntry ||
                    sender.AddressEntryUserType == Outlook.OlAddressEntryUserType.olExchangeRemoteUserAddressEntry)
                {
                    exchUser = sender.GetExchangeUser();

                    if (exchUser != null)
                    {
                        return exchUser.PrimarySmtpAddress;
                    }
                    else
                    {
                        return null;
                    }
                }
                else
                {
                    return sender.PropertyAccessor.GetProperty(PR_SMTP_ADDRESS) as string;
                }
            }

            return null;
        }
        finally
        {
            if (ns != null)
            {
                Marshal.ReleaseComObject(ns);
                ns = null;
            }
            if (store != null)
            {
                Marshal.ReleaseComObject(store);
                store = null;
            }
            if (sender != null)
            {
                Marshal.ReleaseComObject(sender);
                sender = null;
            }
            if (exchUser != null)
            {
                Marshal.ReleaseComObject(exchUser);
                exchUser = null;
            }
        }
    }